Middle Gear Oil Seal Replacement

[gleno]

Any of the forum have experience changing the drive shaft yoke oil seal on the middle gear drive?

Mine seams to have reached the end of it's life. The service manuals seem to indicate that the seal can be removed once the driveshaft, swingarm universal joint and and driveshaft yoke are removed.

Can this be done without removing the motor? Looks tight in there.

Any tips would be appreciated, especially advice on removing the drive shaft yoke from the middle gear shaft without dropping the motor (if this is possible).

 

[maxcruiser]

Any of the forum have experience changing the drive shaft yoke oil seal on the middle gear drive?

Mine seams to have reached the end of it's life. The service manuals seem to indicate that the seal can be removed once the driveshaft, swingarm universal joint and and driveshaft yoke are removed.

Can this be done without removing the motor? Looks tight in there.

Any tips would be appreciated, especially advice on removing the drive shaft yoke from the middle gear shaft without dropping the motor (if this is possible).

Middle drive can be removed with engine in the frame. Loosen the two pinch bolts in block above and remove the three bolts on the middle gear and out it comes, need to watch for the shims.

To remove the yoke, best to use a electric impact on the bolt. Should do it.

Mike

 

[gleno]

Middle drive can be removed with engine in the frame. Loosen the two pinch bolts in block above and remove the three bolts on the middle gear and out it comes, need to watch for the shims.

To remove the yoke, best to use a electric impact on the bolt. Should do it.

Mike

Thanks Mike. Can the yoke be removed without removing the driveshaft?

 

[maxcruiser]

Driveshaft and ujoint need to be removed.

Mike

 

[gleno]

OK got it.

Does that mean I'll have to re-set the middle gear lash tolerances or would they not be affected?

 

[maxcruiser]

Should be ok as is - never had to do it on the ones I worked on

Mike

 

[gleno]

Thanks Mike. I'm on to it.:thumbs up:

 

[guvnor]

How did you go with repairing the oil leak ? easy or hard ? Looks like I got the same trouble with my 85 model, just spent a year customising it took it for a test run at the weekend up and down the street, when I got back in the garage had smoke pouring off the exhaust and quite a bit of oil coming out of the rubber dust cover around the uni joint.

 

[sdt354]

OK got it.

Does that mean I'll have to re-set the middle gear lash tolerances or would they not be affected?

It can't hurt to check the lash before taking it apart. That way if you need to order a shim or 2 you'll have it available.
Steve-o

 

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How did you go with repairing the oil leak ? easy or hard ? Looks like I got the same trouble with my 85 model, just spent a year customising it took it for a test run at the weekend up and down the street, when I got back in the garage had smoke pouring off the exhaust and quite a bit of oil coming out of the rubber dust cover around the uni joint.

Check the fluid level in the differential before assuming its engine oil. The diff seals can leak and the fluid can travel up the swingarm and out the rubber boot.

If it is the seal on the output shaft on the back of the motor, it can be disassembled as noted. I would buy an new crush collar if you will be taking off the pinion nut. Careful not to go overboard when tightening the pinion nut during reassembly. If you make it too tight, the yoke will not spin freely and it will collapse the collar too much and require replacement.

Once the pinion nut is removed the assembly comes apart pretty easily. I pushed it apart with a 2 jaw puller. Two jaws on the outside edges of the output shaft and the center bolt against the pinion bolt. Very little effort was required.